Posted By jom Hi Tony. There's lots published on HAZOPs. There is an Australian Standard (I recall it is based on an EC standard). I'm not sure a HAZOP generates a rating as such. I think it identifies points in a process (nodes) that may not be best equipped to safely respond to some abnormal condition. These deficiencies are essentially the output of a HAZOP study, and are then addressed by others. I don't think there is any pass/fail concept. I've never been involved in one - others might have more knowledge. May I ask what industry this applies to in your case?

Posted By Ian Waldram The authoritative guidance on Hazops is published by IChemE, the technique was invented by ICI, in the 1970's. It is used most often for process plant, but can be adapted for many other situations. I've led studies on a solids storage/conveying system, a genetic manipulation lab, simultaneous operations on a small gas platform in addition to many process units. Hazops don't work unless there is a trained + experienced leader, plus the right representatives of both designers and users of the system being studied, plus often an 'outsider' to ask the silly questions everyone else is too embarrassed to bring up. I have experience of a gas plant in which a heater exploded during comissioning - despite us having completed a very well-structured Hazop. There were of course several root causes, but one was that we hadn't included anyone who really understood gas-fired burners (e.g. the vendor) in the Hazop team when we looked at the controls. Risk assessments too need some competence & structure to make them effective - but not to the same extent as a Hazop. A prospective Hazop leader needs both the basic training, then to sit in studies led by an experienced leader, then perhaps to act as recording secretary for a few before attempting to lead. Members of the IOSH Offshore SG could suggest some experienced oil industry hazop leaders if you need one, whether for exploration or production sites.